Improvement in sewing-machines



T. J. W. ROBERTSON.

Sewing Machine: No. 18,470.

Patented Oct. 20; 1857,

N. PETERS. PlhOlO-Lfllmgnlplvcr, Wnshinglml, D. cv

- UNITED STATES PATENT QFFTQE.

T. J. w. EoBERTsoN, or NEW YORK, N. Y.

IMPROVEMENT IN SEWING-MACHINES.

Specification forming part of Letters Patent No. [8.470, dated October20, 1857.

T0 (0Z3 who/1'1, it may concern.-

Be it known that I, T. J. WV. RoBERTsoN, of the city, county, and Stateof New York, have invented a new and useful Improvement inSewing-Machines; an d I do hereby declare that the following is a full,clear, and exact de-- scription of the same, reference being had to theaccompanying drawings, making part of this specification, in whichFigure 1 is a. front view, showing one of the angles which the twoneedles form in relation to each other, and also showing the obliqueneedle in two positions. Fig. 2 is a side view, showing the other angleformed by the two needles. Fig. 3 is a view showing the position of theneedles as the second needle, j, enters the loop of the first needle, i.Fig. 4 is a view showing the first needle, t, (after it has passedthrough its own loop,) passing through the loop of the second needle, j.Fig. 5 shows the loops of both needles around the first needle, i,previous to the tightening of the stitch. Fig. 6 shows the secondneedle, j, operating as a looper to form the single-thread or chainstitch, taking the loop from the needle Fig. 7 represents the secondneedle, 7, holding the loop for the first needle, 41, to pass through.Fig. 8 shows the position of the needles when this stitch is completed.Fig. 9 is a magnified view of the two-thread stitchmade by this machine.

This improvement consists, first, in a new stitch, which I call thedouble back-stitch, which is made as follows; Pass a loop of threadthrough the fabric to be sewed; then pass through the fabric and throughthe first loop (from the same side of the fabric as the first loop)another loop from another thread; then pass through the fabric anotherloop from the first thread through its own first loop and the loop ofthe second thread.

The second part of my invention consists in a machine for making theforegoing-described stitch by means of two needles working at suchangles to each other that they cross ben eath the table and. workthrough each others loops. r

A A A is the frame of the machine, which may be made of any fanciful orconvenient form.

B is a needle-holder working vertically between guides C 0, attached tothe frame A.

D-is another needleholder set to run in such a manner as regards theholder B that the needles '6 j shall cross each other below the table S,said holder D having such a relative position to the holder B as to formwith it the angles shown in Figs. 1 and 2.

Motion is imparted to the holder B by turning the handle E, which isattached to one end of a shaft, F, which runs through a tube, F, saidtube serving as a bearing for the shaft. The other end of the shaft F isbent so as to form a crank, G, which operates the holder B r by means ofthe pitman H, said ,pitman being connected to the holder 13 by thescrew 1. The second needle-holder D derives its motion from a pin, J, onthe holder 13, which pin works in in a slot, K, in the driver L. Thisdriver works 011 a pivot, a, screwed into the guide 0, and operates theholder D by means of a pin, b, attached to said holder and working in aslot, 0, in the other end of the driver L.

M is the foot for holding down the fabric R to the table S of themachine, said foot being fastened to the guide 0 by the screws (1 e.

N O are guides for the holder D, attached to guide 0 by screwsfff. Theguide N is slotted to allow the holder D a vibrating motion, as shown inFig. 1. g

P is a spring attached to the guide 0, imparting a backward motion toholder D after the needle has risen clear of the fabric.

g is a set-screw passing through the guide N to limit the backwardmotion of the holder D. U and V are two spools running on spindle WV,attached to frame A.

70 Z are tension-pins, around which the threads are wound to give therequisite tightness to the stitch.

' m. a 0 p are th read-guides to carry the thread to the needles 1' j.

The operation of the machine, when mak ing the double back stitch may bedescribed as follows: The machine being fastened to a table in anyconvenient manner, the needle i is raised to its highest point, and theupper end of the driver L is slipped from under the pin J, therebylifting the needle j clear of the table, so that the cloth or materialto be sewed can be introduced between the foot M and table S. Theneedle-holder D is now returned to its proper position and the machineis ready for use. The operator should now take hold of the fabric withhis left hand, giving'it a steady moderate pull toward himself, and atthr same time working the machine by turning the handle E with his righthand. As the.

first needle, 2', descendsthe second needle, j, rises, and as it clearsthe fabric the spring P gives the needle-holder D a backward motioncorresponding to the length of stitch. The extent of this motion isregulated by the holder D coming in contact with the point of thesetscrew As the first needle, 1', begins to rise it forms a loop in itsthread, and the second needle, j, in its downward motion, passes throughsaid 100p, taking with it a loop of its own thread, asseen in Fig. 3. Asthe first needle, 2', completes its upward motion the fabric is movedthe length of astitch. This causes the second needle, j, to assume theposition shown in black in Fig. 1, the red outline showing the positionof the needle previous to this motion. The forward motion of holder D islimited by said holder coming in contact with the fixed screw h, and bythe needle pressing against the stop T. This stop serves to sustain theneedlej against any extra pull on the fabric, which would otherwisebreak or bend it. WVhen the second needle, j, begins to rise,

it forms a loop also, and the first needle, 77, as

it descends, passes through its own loop (the said loop being held inproperposition by needle j) and through the loop of the said secondneedle, as shown in Figs. 4 and 5. As the first needle, i, finishes itsdownward mo tion the loop of said first needle, 2 is liberated by therising of the second needle and is drawn tight around the first needle,thereby finishing the stroke. A succession of these movements completesa line of what I call double back-stitching.

To make the single-thread or tambour stitch it is only necessary toremove the thread from the second needle, j, when it immediatelybecomesa simple looper, to take the thread from the needle 1, as seen inFig. 6, and hold it in position for the needle '6 to pass through it inits next descent, as shown in Fig. 7. The operation of the machine inmaking this stitch may be briefly described as follows: The nee dlei, onits first descent, carries aloop of thread through the fabric B. As theneedle 1' rises the loop bows or spreads out, so that the needlej (whichis now making its downward motion) passes through said loop, as seeninFig. 6. \Vhen the needle 1' has completed its upward motion and theneedle j its descent, the loop of thread is held open by needle j, asshown in Fig. 7, for needle i to pass through in its next descent. Asthe needle 1' descends the needle j, by rising, casts off the loop,which is drawn tight round the needle i, as represented in Fig. 8. Acontinuation of these motions makes a line of tambour stitching.

I do not claim, broadly, the employment of two needles for the purposeof sewing cloth, for they are seen in the patents of O. Avery, October19, 1852, to May 9, 1854.

' W hat I claim as new, and desire to secure by Letters Patent, i's

1. Forming aseam' by passing aloop of thread through the fabric to besewed, then passing through the fabric and through the first loop a looptaken from another thread from the same side of the material as theprevious loop, then passing through the fabric another loop from thefirst thread through its own first loop and the loop of the secondthread, thus mak ing a line of stitching which I call doubleback-stitching.

2. The arrangement and combination of the needles '6 andj, or theirequivalents, substantially as described.

August 6, 1857.

, T. J. XV. ROBERTSON.

Vii nesses \VILLIAM Tnson, A. E. BEACH.

